SHANGHAI -- A fleet of three Chinese naval ships left Shanghai Sunday morning for public relations visits to more than 20 countries.

The fleet, composed of missile destroyer Changchun, missile frigate Jingzhou and supply ship Chaohu, will tour Asia, Europe, Africa and Oceania for nearly 180 days.

The visits will convey friendship, deepen military communication and cooperation and show a good image of the Chinese navy, according to Miao Hua, Political Commissar of the Chinese People's Liberation Army (PLA) Navy, who saw the fleet off.

All the three ships were domestically made. It is the maiden voyage of the Jingzhou, commissioned in 2016. The other two ships have conducted many escort, drill and patrol missions.

Sunday marks the 68th anniversary of the establishment of the PLA Navy.